Extensions are sticking now, between sessions.
It happened after incremental upgrades, this morning.
Code:
Commit Log for Sat Sep 21 06:45:34 2013
Upgraded the following packages:
gnome-control-center (1:3.9.92-0ubuntu1~saucy4) to 1:3.9.92-0ubuntu1~saucy5
gnome-control-center-data (1:3.9.92-0ubuntu1~saucy4) to 1:3.9.92-0ubuntu1~saucy5
libgnome-control-center1 (1:3.9.92-0ubuntu1~saucy4) to 1:3.9.92-0ubuntu1~saucy5
libqt5concurrent5 (5.0.2+dfsg1-7ubuntu8) to 5.0.2+dfsg1-7ubuntu9
libqt5core5 (5.0.2+dfsg1-7ubuntu8) to 5.0.2+dfsg1-7ubuntu9
libqt5dbus5 (5.0.2+dfsg1-7ubuntu8) to 5.0.2+dfsg1-7ubuntu9
libqt5gui5 (5.0.2+dfsg1-7ubuntu8) to 5.0.2+dfsg1-7ubuntu9
libqt5network5 (5.0.2+dfsg1-7ubuntu8) to 5.0.2+dfsg1-7ubuntu9
libqt5opengl5 (5.0.2+dfsg1-7ubuntu8) to 5.0.2+dfsg1-7ubuntu9
libqt5opengl5-dev (5.0.2+dfsg1-7ubuntu8) to 5.0.2+dfsg1-7ubuntu9
libqt5printsupport5 (5.0.2+dfsg1-7ubuntu8) to 5.0.2+dfsg1-7ubuntu9
libqt5sql5 (5.0.2+dfsg1-7ubuntu8) to 5.0.2+dfsg1-7ubuntu9
libqt5sql5-mysql (5.0.2+dfsg1-7ubuntu8) to 5.0.2+dfsg1-7ubuntu9
libqt5sql5-sqlite (5.0.2+dfsg1-7ubuntu8) to 5.0.2+dfsg1-7ubuntu9
libqt5test5 (5.0.2+dfsg1-7ubuntu8) to 5.0.2+dfsg1-7ubuntu9
libqt5widgets5 (5.0.2+dfsg1-7ubuntu8) to 5.0.2+dfsg1-7ubuntu9
libqt5xml5 (5.0.2+dfsg1-7ubuntu8) to 5.0.2+dfsg1-7ubuntu9
qt5-default (5.0.2+dfsg1-7ubuntu8) to 5.0.2+dfsg1-7ubuntu9
qt5-qmake (5.0.2+dfsg1-7ubuntu8) to 5.0.2+dfsg1-7ubuntu9
qtbase5-dev (5.0.2+dfsg1-7ubuntu8) to 5.0.2+dfsg1-7ubuntu9
qtbase5-dev-tools (5.0.2+dfsg1-7ubuntu8) to 5.0.2+dfsg1-7ubuntu9
qtbase5-doc (5.0.2+dfsg1-7ubuntu8) to 5.0.2+dfsg1-7ubuntu9
Take your pick.
Probably the g-c-c upgrades...